JPS6118287Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vacuum check valve used in a negative pressure booster for boosting a brake master cylinder or the like of an automobile.

Generally, in a negative pressure booster that uses the intake manifold of an automobile engine as a vacuum source and uses the resulting negative pressure as power, the intake manifold is placed between the negative pressure chamber, which should constantly store negative pressure, and the intake manifold. A check valve is provided to prevent negative pressure from flowing back from the negative pressure chamber to the intake manifold and to maintain negative pressure in the negative pressure chamber even if the negative pressure decreases.

Conventionally, such a check valve has the structure shown in FIG. 1. A body 4 with a valve body 3 therein is disposed on a casing side wall 1 of a negative pressure chamber in which negative pressure is to be stored, through a sealing grommet 2 made of an elastic material. 4a
is opened and closed by the valve body 3. A cap 5 for locking the valve body 3 is attached to the opening end of the body 4 on the negative pressure chamber side by welding or a snap fit, and a negative pressure introduction pipe 6 is provided on the side connected to the intake manifold of the engine. ing.
The valve body 3 is a valve spring 7 installed inside the body 4.
It is biased toward the cap 5 side through the valve, and is opened by the negative pressure of the intake manifold when the engine is running, and closed by the valve spring 7 when the negative pressure of the intake manifold decreases. to be accomplished.
This allows the negative pressure chamber to be constantly stored.

However, in the above-described check valve, when the cap 5 is attached to the body 4, the cap 5 must be attached by welding or snap fitting against the valve spring 7, resulting in extremely poor workability. In addition, it is necessary to maintain sufficient airtightness between the body 4 and the cap 5, and the joining process requires time and costs for the cap 5 or the joining means are increased, which is uneconomical.

The present invention was developed in view of the above circumstances, and aims to improve workability and airtightness, as well as to provide an economical vacuum check valve. An elastic grommet that airtightly fits into the opening formed in the side wall of the casing of the negative pressure chamber to be stored, and a negative pressure introduction pipe that airtightly fits into the inner periphery of the grommet and communicates with the negative pressure source. In the vacuum check valve having a body of the same type, a valve body locking portion extending toward the center is formed at the negative pressure chamber side opening end of the elastic grommet, and a valve body locking portion extending toward the center is formed on the body side of the valve body locking portion. The valve body for opening and closing the fluid passage is seated on the formed valve seat surface.

Hereinafter, the present invention will be described in detail with reference to illustrated embodiments.

In FIG. 2, reference numeral 10 denotes a check valve disposed in an opening formed in the casing side wall 12 of a negative pressure chamber 11 in which negative pressure is to be stored. and opens and closes a fluid path to and from a source (not shown). In this case, the negative pressure chamber 11 is a chamber that maintains a vacuum for operating a power booster mechanism of a brake device (not shown), and the negative pressure source is an intake manifold of the engine. The check valve 10 is composed of a body 14 containing a valve body 13 and a sealing grommet 15 made of an elastic material such as rubber. The body 14 is composed of a valve chamber 16 penetrating into the negative pressure chamber 11 and a negative pressure introduction pipe 17 connected to the intake manifold. The grommet 15 that maintains airtightness is fitted. This grommet 15 is fitted into the opening of the casing side wall 12 through a groove on the outer circumferential surface, and has a locking portion that extends by bending one opening end toward the center and locking the valve body 13. 18 is formed. The locking portion 18 forms a contact surface with the valve seat 13a of the valve body 13 on the valve seat surface. The valve body 13 is disposed within the valve chamber 16a of the valve chamber portion 16, and is connected to the locking portion 18 via the valve spring 19.
The side is always energized.

However, according to the vacuum check valve of the present invention,
A grommet 15 is fitted into the opening of the casing side wall 12. On the other hand, the valve body 13 and the valve spring are housed in the valve chamber 16a of the body 14, and the body 14 is press-fitted into the grommet 15 and assembled. Therefore, by press-fitting the body 14 into the grommet 15, the valve body 13 is locked with the valve seat 13a abutting the locking portion 18, and the urging force of the valve spring 19 gradually acts to lock the locking portion 18. Pressed by

To explain the operation of the check valve assembled in this way, first, when the car engine starts,
Due to the negative pressure of the intake manifold, the valve body 13 is attracted in the direction of the arrow in the figure against the valve spring 19, and the check valve 1 is
Release 0. This maintains negative pressure in the negative pressure chamber 11 and serves as an operating source for the power booster mechanism. Furthermore, in the event that the negative pressure in the intake manifold decreases, the valve body 13 is biased by the valve spring 19 and comes into contact with the locking portion 18 to close the flow path.

Next, FIGS. 3 and 4 show other embodiments of the present invention, in which the same parts as those in FIG. 2 are given the same reference numerals and their explanation will be omitted.

In this case, the vacuum check valve 10' shown in FIG. 3 is provided with a guide shaft 20 protruding on the axis within the valve chamber 16a of the body 14', and a cylindrical body 21 is provided in the valve body 13'. The body portion 21 is slidably fitted onto the guide shaft 20. The guide shaft 20 is provided with a protrusion 20a at its distal end to prevent the valve body 13' from coming off, and a fluid passage 22 is formed at its rear end support. Then, the valve body 13'
slides along the guide shaft 20 to open and close the fluid flow path.

In addition, the vacuum check valve 10'' shown in FIG. 4 is provided with a part of the negative pressure introduction pipe 17 extended into the valve chamber 16a, and the support shaft 24 of the valve body 13'' is slidably attached to the extended portion 23. It has been inserted. A protrusion 23a for preventing slippage is provided on the inner surface of the extension portion 23 and the tip of the support shaft 24.
and 24a, and the fluid passage 25 from the valve chamber 16a to the negative pressure introduction pipe 17 is connected to the valve chamber 16a.
It is provided on the rear end wall. The valve body 13'' is opened and closed by the support shaft 24 sliding within the extension portion 23.

As described above, according to the vacuum check valve of the present invention, the negative pressure chamber side opening end of the grommet interposed between the opening in the casing side wall and the body extends toward the center of the valve body. Since the locking part was formed,
When assembling a check valve, the valve body can be pressed against the locking part and placed in the specified position within the body by simply press-fitting the body into the grommet, which is much easier than when using a conventional cap. It is possible to improve sexual performance. Further, since the locking portion is integrally molded on the grommet, the conventional cap is not required, and it is possible to improve airtightness and economical efficiency. Furthermore, in the unlikely event that backfire pressure occurs in the intake manifold due to backfire that occurs when starting the engine,
The elastic force of the grommet can absorb internal spinal pressure, thereby preventing damage to the check valve.

[Brief explanation of the drawing]

Figure 1 is a conceptual cross-sectional view of a conventional vacuum check valve.
FIG. 2 is a conceptual cross-sectional view showing a vacuum check valve according to one embodiment of the present invention, and FIGS. 3 and 4 are conceptual cross-sectional views showing vacuum check valves according to other embodiments of the present invention. 10,10',10''...Vacuum check valve, 11...
Negative pressure chamber, 12... Casing side wall, 13, 1
3', 13''... Valve body, 14, 14', 14''... Body, 15... Grommet, 18... Locking part, 1
9...Valve spring.

Claims (1)

[Scope of utility model registration request] An elastic grommet that airtightly fits into the opening formed in the side wall of the casing of the negative pressure chamber that is to store negative pressure at all times; In the vacuum check valve having a body in which a pressure introduction pipe is formed, a locking portion of the valve body extending toward the center is formed at the opening end of the elastic grommet on the negative pressure chamber side, and A vacuum check valve characterized in that a valve element for opening and closing the fluid passage is seated on a valve seat surface formed on the body side of the stop part.